Grassroots conservative activists are attacking the Karl Rove-backed Super PAC American Crossroads as ineffective in a letter to top-dollar Republican donors in an effort to protest against the group’s pledge to play a role in Republican primaries.

Led by Brent Bozell, the founder and president of the Media Research Center, the effort is an attempt to sabotage the Conservative Victory Project backed by Crossroads and to support electable candidates in GOP nominating contests. The letter highlights a 1.29 percent return on investment for the Rove group calculated by the non-partisan Sunlight Foundation. It is unclear how the letter will be delivered to the top donors of the Rove effort, since a large share of them have remained anonymous.

“As conservative leaders who represent millions of grassroots conservatives, we strongly urge you to consider this information as you are making your decisions about political giving in the future,” the letter closes.

Crossroads spokesman Jonathan Collegio didn’t address the contents of the letter when asked to comment on the conservative effort. “We are relentlessly focused on stopping President Obama’s agenda, winning a conservative majority in the Senate and expanding the conservative majority in the House,” he said.

The full text of the letter:

You have likely heard over the last several weeks about a new effort called the Conservative Victory Project that will be supported by Karl Rove and the Crossroads organizations. Their stated purpose is to identify conservative candidates in Republican primaries capable of winning elections. As leaders in the conservative movement who have been active in conservative and Republican politics for decades, we are writing to set the record straight.

The 2012 election cycle saw our first billion-dollar campaign. Recently, the non-partisan Sunlight Foundation did an analysis of the money spent. They measured the effectiveness of political spending by the amount of money spent on a successful effort—either electing a chosen candidate or defeating a chosen candidate. They found that the success rate of the Crossroads effort was 1.29%.

Now, in an attempt to explain the astonishingly low return on the hundreds of millions of dollars investment in Crossroads, Karl Rove and others are attempting to blame conservatives and the tea party. But a simple analysis shows this to be simply untrue. In 2012, the only Senate Republican winners were Jeff Flake, Deb Fischer, and Ted Cruz—all of whom enjoyed significant tea party and conservative support. Meanwhile, more moderate candidates like Tommy Thompson, Heather Wilson, Rick Berg, and Denny Rehberg went down to defeat despite significant support from Crossroads.

It was firmly expected that Republicans would capture the Senate in 2012. It is inexcusable that they failed and, in fact, lost two seats. The facts speak for themselves. It was not conservatives. Not one moderate Republican challenger won. According to the Sunlight Foundation, not one Senate challenger supported by Crossroads won.

There was another, equally important reason Republicans fared so poorly: Groups like Crossroads squandered hundreds of millions of dollars in what were arguably the most inept campaign advertising efforts ever.

Mr. Rove and his allies must stop blaming conservatives for his disastrous results. It is time for him to take ownership of his record. He must also stop posturing himself as a conservative: his record supporting wasteful government spending and moderate candidates over conservatives spans decades.

No matter how he positions himself in this attempt at damage control, Mr. Rove’s efforts will not elect the type of leaders who will come to Washington to fight for conservative principles. In fact, they are likely to stifle the emergence of candidates like Marco Rubio, Pat Toomey, and Rand Paul. Further, the model that will be employed by the Conservative Victory Project has proven to be ineffective and a waste of political resources.

As conservative leaders who represent millions of grassroots conservatives, we strongly urge you to consider this information as you are making your decisions about political giving in the future.

During the 2012 Presidential campaign the Right Wing Christian fanatic faction of the GOP launched its “War on Women” campaign.The War on Women movement of the GOP cost the party 1000’s of female votes.The recent passage of an anti-abortion bill by the Arkansas State Legislature clearly indicates to me that the GOP’s War on Women movement is continuing on.The Arkansas anti-abortion law was pushed through to passage over the Governor’s veto by a majority of white male Right Wing Christian fanatic lawmakers.While this anti-abortion law might be generally popular with voters in the Bible Belt State of Arkansas, on the national level it will cause the GOP to lose more voters (especially women).The Right Wing Christian fanatics are an absolute plague on the GOP.Unless the GOP can rid itself of this plague it will continue to deteriorate and will eventually become nothing but words in history books.

To call Republicans members of a political party is a misunderstanding of the situation. Republicanism is a medically verified personality disorder. In short--Republicans don't need votes, they need medication.

Karl Rove will not sifle the development of the likes of Rand Paul and Marco Rubio. They will do a fine job all by their lonesome, stifling their development and harming the profile of those near them ideologically.

@MarcusTaylor So, what you are saying is being a Republican is actually a form of mental illness. Taken one step further, all Republicans would then be ineligible to own guns because the mentally ill are prohibited from doing so.